A mysterious message is locking Google Docs users out of their files

Imagine you're working on a Google Doc when, seemingly out of nowhere, your ability to edit the online file gets revoked. What you see instead is an error message indicating that you've violated Google's terms of service.

For anyone who stores work in the cloud, suddenly being unable to access your data — especially due to a terms of service violation — may sound scary. And it's really happening to some people, according to reports on Twitter. Rachael Bale, a wildlife crime reporter for National Geographic, said Tuesday that a draft of her story was "frozen" by Google.

Has anyone had @googledocs lock you out of a doc before? My draft of a story about wildlife crime was just frozen for violating their TOS.

In response to some of these reports, a Google employee tweeted that the team handling Google Docs was looking into the matter. Later Tuesday, Google said in a statement that it had "made a code push that incorrectly flagged a small percentage of Google Docs as abusive, which caused those documents to be automatically blocked. A fix is in place and all users should have full access to their docs."

Although the error appeared to be a technical glitch, the fact that Google is capable of identifying "bad" Google Docs at all is a reminder: Much of what you upload, receive or type to Google is monitored. While many people may be aware that Gmail scans your emails — for instance, so that its smart-reply feature can figure out what responses to suggest — this policy extends to other Google products, too.

"Our automated systems analyze your content to provide you personally relevant product features, such as customized search results, and spam and malware detection," reads the terms of service for Google Drive, the suite of productivity tools of which Google Docs is a part. "Google’s Privacy Policy explains how we treat your personal data and protect your privacy when you use Google Drive."

If you visit Google's privacy policy, you'll find that Google is up front there, too, about the data it collects.

"We collect information about the services that you use and how you use them, like when you watch a video on YouTube, visit a website that uses our advertising services, or view and interact with our ads and content," it says.

What does it mean when Google says "collect information"? This page says more:

"This includes information like your usage data and preferences, Gmail messages, G+ profile, photos, videos, browsing history, map searches, docs, or other Google-hosted content. Our automated systems analyze this information as it is sent and received and when it is stored."

Google explicitly refers to docs — albeit in a lower-case fashion — as an example of the type of content from which Google extracts information. I've asked Google for clarification on whether they actually read the contents of a person's Google Docs and will update if I get a response.

Update: On Tuesday afternoon, Google said that it does not technically read files, but instead uses an automated system of pattern matching to scan for indicators of abuse. Though it can identify clusters of data that might suggest a violation, the system does not pull meaning from the content, according to a company spokesperson.

Brian FungBrian Fung covers business and technology for The Washington Post. Before joining The Post, he was the technology correspondent for National Journal and an associate editor at the Atlantic. Follow